Электронный компас

Разработка электронного компаса на основе датчиков: магнитометра, акселерометра и гироскопа. Данное устройство будет определять направление на северный магнитный полюс как при горизонтальном положении, так и при отклонениях от горизонтальной плоскостиDevelopment of electronic compass based on sensors: magnetometer, accelerometer and gyroscope. This device will determine the direction to the North magnetic pole both in the horizontal position and in deviations from the horizontal plan

Electrostatic energy storage in antiferroelectric like perovskite

International audienceLead-free ferroelectric Na0.5Bi0.5TiO3 (NBT) and NBT-doped Ln (Ln = Er and Ho) in both bulk and thin films forms were processed via solid-state reaction and solution deposition respectively. SEM investigations showed dense samples with fine-grained and smooth microstructure for thin films. A pure perovskite structure was observed by the X-ray diffraction for all specimens. The frequency dependences of the dielectric constant and loss tangent were investigated at room temperature and revealed a decrease in the dielectric losses with the introduction of the lanthanide element. The energy storage density (Wrec) was calculated using the obtained P–E loops. The stored and delivered energies were found depending on the form and composition of the sample

Solidification of metallic alloys under Magnetic fields.

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Crystal Growth of Silicon for Photovoltaics

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Effect of Travelling Magnetic Field on the Directional Solidification of refined Al-3.5 wt %Ni alloys

The specific objective of the paper is to investigate the effect of fluid flow on the development of a dendritic microstructure and more particularly on the columnar and equiaxed solidification regimes. A gradient furnace (BATMAF) with a possibility of applying a travelling magnetic field was designed for the solidification of aluminium-based alloys. The travelling magnetic field (TMF) drives a forced flow in the liquid above the solidifying interface. Some experiments are achieved in this furnace on an Al-Ni3.5wt% refined alloy. As a result, a significant change of the microstructure due to the transversal melt flow is observed. This work is performed in the framework of the CETSOL/MICAST Microgravity Application Projects of the European Space Agency (ESA)

Influence of forced/natural convection on segregation during the directional solidification of Al-based binary alloys.

International audienceWe analyzed the columnar solidification of a binary alloy under the influence of an electromagnetic forced convection of various types and investigated the influence of a rotating magnetic field on segregation during directional solidification of Al-Si alloy as well as the influence of a travelling magnetic field on segregation during solidification of Al-Ni alloy through directional solidification experiments and numerical modeling of macrosegregation. The numerical model is capable of predicting fluid flow, heat transfer, solute concentration field, and columnar solidification and takes into account the existence of a mushy zone. Fluid flows are created by both natural convection as well as electromagnetic body forces. Both the experiments and the numerical modeling, which were achieved in axisymmetric geometry, show that the forced-flow configuration changes the segregation pattern. The change is a result of the coupling between the liquid flow and the top of the mushy zone via the pressure distributionalong the solidification front. In a forced flow, the pressure difference along the front drives a mush flow that transports the solute within the mushy region. The channel forms at the junction of two meridional vortices in the liquid zone where the fluid leaves the front. The latter phenomenon is observed for both the rotating magnetic field (RMF) and traveling magnetic field (TMF) cases. The liquid enrichment in the segregated channel is strong enough that the local solute concentration may reach the eutectic composition